The invention relates to improvements in methods of and in apparatus for adjusting or actuating torque transmitting systems, particularly for adjusting clutches in the power trains of motor vehicles. Still more particularly, the invention relates to improvements in methods and apparatus which can be resorted to with advantage for adjusting the transmission of torque from a prime mover (such as the internal combustion engine of a motor vehicle) to a transmission (e.g., a manual transmission having a plurality of gear ratios). The transmission of torque can be effected by a clutch (e.g., a friction clutch) which can be installed upstream or downstream of the transmission.
Certain presently known apparatus for actuating adjustable clutches or analogous torque transmitting systems are disclosed, for example, in published German patent application No. 40 13 299 and in U.S. Pat. Nos. 4,723,642 and 5,029,683.
The published German patent application No. 40 13 299 discloses a transmission wherein an elastic element is built into a lever which is to be actuated by hand to select the gear ratio of the transmission. An analog sensor is provided to detect the extent of deformation or displacement of such elastic element during manual shifting of the lever for the purpose of changing the gear ratio of the transmission. The U.S. Pat. Nos. 4,723,642 and 5,029,683 disclose manual transmissions with levers having built-in switches which are actuated in response to manipulation of the lever for the purpose of selecting a different gear ratio.
An object of the invention is to provide a simple, compact and reliable apparatus for actuating a clutch or another adjustable torque transmitting system, particularly in the power train between a prime mover and a multiple gear ratio transmission in a motor vehicle.
Another object of the invention is to provide an apparatus which need not employ a substantial number of complex and expensive sensors or other devices for monitoring the movements and/or other variable parameters of component parts of a manual transmission in the power train of a motor vehicle.
A further object of the invention is to provide the above outlined apparatus with novel and improved means for ascertaining the presence or the absence of an intent on the part of the operator of a motor vehicle to shift a manual transmission into a different gear ratio.
An additional object of the invention is to provide an apparatus which automatically ensures convenient shifting of the transmission into a different gear ratio as soon as the operator provides a detectable indication that she or he intends to effect such shifting.
Still another object of the invention is to provide an apparatus whose operation is not affected, or is not unduly affected, by evental changes in the condition of one or more component parts of the power train during the useful life of a motor vehicle.
A further object of the invention is to provide an apparatus whose operation remains at least substantially unchanged during the entire life span of the power train in a motor vehicle.
Another object of the invention is to provide a novel and improved manual transmission for use in conjunction with the above outlined apparatus.
An additional object of the invention is to provide an apparatus which invariably ensures timely disengagement of the clutch in the power train of a motor vehicle when the operator of the vehicle proceeds to change the speed ratio of a manual transmission in such power train.
Still another object of the invention is to provide a novel and improved combination of a clutch, a manual transmission, various sensors and a central control unit for use in the above outlined apparatus.
A further object of the invention is to provide an apparatus which can reliably ascertain an operator""s intent to change the ratio of any one of a number of different manual transmissions which are utilized in the power trains of motor vehicles to receive torque from a combustion engine or another suitable prime mover by a way of a friction clutch or another torque transmitting system.
Another object of the invention is to provide a novel and improved method of adjusting a torque transmitting system in response to detection of the intention by an operator of a motor vehicle to change the ratio of a manual transmission.
An additional object of the invention is to provide a novel and improved method of ascertaining the intent of the operator of a motor vehicle to change the ratio of a manual transmission.
Still another object of the invention is to provide a method which is not affected by eventual wear and/or other undesirable changes of the condition or characteristics of the component parts of the above outlined apparatus.
A further object of the invention is to provide a novel and improved method of ensuring timely changes in the condition of a clutch or another suitable torque transmitting system in the power train of a motor vehicle when the operator of the vehicle furnishes a detectable indication that she or he intends to actuate the manual transmission in the power train.
Another object of the invention is to provide a method which can be practiced by resorting to a simple, compact and relatively inexpensive apparatus and which can detect the intent of the operator of the vehicle to change the ratio of a manual transmission as soon as such intent becomes detectable in any one of a number of different ways.
An additional object of the invention is to provide a power train which embodies or which can be combined with the above outlined apparatus.
Still another object of the invention is to provide a motor vehicle which embodies the above outlined apparatus.
One feature of the instant invention resides in the provision of an apparatus for actuating an adjustable system (such as an engageable and disengageable clutch, e.g., a friction clutch) for transmitting torque in a power train including a tranmission (e.g., a manual transmission) having a plurality of gear ratios (e.g., forward gear ratios one to five or one to six, a reverse gear ratio and a neutral gear ratio), at least one external ratio selecting member (e.g., a pivotable lever having a knob which can be engaged by a hand of the operator of a motor vehicle in which the power train is being put to use), at least one internal gear shifting member (e.g., a shaft in the case of the transmission) and a connection between the external and internal members. The improved apparatus comprises monitoring means including at least one sensor (e.g., a potentiometer or a Hall generator) for transmitting first signals which denote changes of at least one variable parameter of at least one component of a plurality of components including the at least one external member, at least one internal member and at least one element of the connection forming part of the transmission), a control unit (e.g., a computerized central control unit) having means for processing the first signals and for generating second signals as a function of the first signals, and means (e.g., an electric motor) for adjusting the torque transmitting system in response to the second signals.
The power train can be installed in a motor vehicle and can further include a prime mover (such as an internal combustion engine). The connection between the external and internal members of the transmission can include a resilient element (e.g., a coil spring), and the aforementioned components can include a second element forming part of the connection and being connected with the at least one external member, and a third element also forming part of the connection and secured to the at least one internal member. The at least one sensor can be operative in a power flow between the resilient element and one of the external and internal members.
At least one of the second and third elements of the connection can include or constitute a mobile element, and the at least one sensor can be mounted and designed to monitor the extent of movement of such mobile element.
The at least one external member can be mounted for movement between a plurality of positions each of which is indicative of a different force which is required to move the at least one external member to the respective position.
Otherwise stated, the at least one external member is movable through a plurality of different distances each of which is indicative of a different force which is required to move the at least one external member through the respective distance.
For example, the arrangement can be such that the at least one external member is movable from a first position to a plurality of additional positions through different distances each of which is indicative of a different force required to move the at least one external member to the respective additional position. One of these distances can be indicative of a threshold value of such force.
As mentioned above, the connection between the at least one external member and the at least one internal member of the transmission can comprise a resilient element, and the at least one external member can be arranged for movement between a plurality of different positions each of which is indicative of a different force required to move the at least one external member to the respective position. The first signals can denote the positions of the at least one external member, and the second signals can denote the intended movement of the at least one external member to select a gear ratio when the first signals denote that the position of the at least one external member, as detected by the at least one sensor, matches a predetermined threshold position or departs from such predetermined threshold position.
The processing means can include means for comparing the second signals with a third signal denoting a threshold of a force which is to be applied to the at least one external member to select a given transmission ratio, and means for generating second signals denoting the intended movement when the first signals denote that the position of the at least one external member (a) matches or (b) is other than the predetermined threshold position. The transmission can be constructed and assembled to maintain the at least one member in a selected position with a preselected retaining force; the second signals which denote the intended movement of the at least one external member are generated when the respective first signals denote that the force which is required to move the at least one external member to the sensor-detected position at least matches the preselected force. The ratio of the magnitude of the force which is required to move the at least one external member relative to the magnitude of the retaining force is or can be between about 0.5 and 0.95, preferably between about 0.6 and 0.9.
As mentioned above, the connection between the internal and external members of the transmission can comprise a resilient element (such as a coil spring or a synthetic plastic resilient element), and the at least one external member of the transmission can be installed for movement through a plurality of different distances each of which is indicative of a different force required to move the at least one external member through the respective distance. The first signals can denote the distances which are covered by the at least one external member, and the second signals can denote the intended movement of the at least one external member to select a gear ratio when the first signals denote that the distance which has been covered by the at least one external member and which has been detected by the at least one sensor either matches or is other than a predetermined threshold distance. In such apparatus, the processing means can include means for comparing the second signals with a third signal which denotes a threshold of a force to be applied to the at least one external member in order to select a given transmission ratio, and for generating second signals which denote the intended movement when the first signals indicate that the distance which has been covered by the the at least one external member either matches or is other than the predetermined threshold distance. Here, again, the transmission can be constructed and assembled to maintain the at least one external member in a selected position with a preselected retaining force, and the second signals which denote the intended movement of the at least one external member are generated when the force which is required to move the at least one external member through the sensor-detected distance at least matches the preselected retaining force. In this embodiment, too, the magnitude of the force which is required to move the at least one external member relative to the magnitude of the preselected retaining force can be between about 0.5 and 0.95, preferably between about 0.6 and 0.9.
If the at least one external member is movable through a plurality of different distances and the first signals denote such distances, the signal generating means of the control unit can be designed to generate a second signal which denotes a threshold distance when the respective first signal indicates a movement of the at least one external member through a predetermined distance.
The arrangement is normally such that the at least one external member is movable through a plurality of different distances in response to the application or exertion of different forces; the signal generating means of the control unit can be designed to generate a second signal denoting a force having a threshold value when the respective first signal or signals denote a movement of the at least one external member through a predetermined distance.
The signal generating means of the control unit can be set up to generate a second signal indicating an intent to shift the transmission into a selected gear ratio by way of the at least one external member in response to the processing of a predetermined first signal, e.g., a signal having a predetermined intensity or another characteristic. Such predetermined first signal can be a threshold signal. A second signal denoting an intent to shift into a selected gear ratio can be generated in response to the generation (by the signal processing means of the control unit) of a signal having a characteristic which is the difference between the characteristics of a plurality of first signals. Alternatively, the signal which induces the signal generating means of the control unit to transmit a second signal can be a quotient of differences between the characteristics of a plurality of first signals.
The monitoring means can include a plurality of sensors each having an output operatively connected with the control unit to transmit signals denoting a variable parameter of a discrete component of the aforementioned plurality of components; the signal generating means of the control unit in such apparatus can be designed to generate a second signal denoting an intent to shift the transmission into a selected gear ratio by way of the at least one external member in response to the processing of a given signal from one of the sensors. Such given signal can constitute a threshold signal. The second signal which denotes an intent to shift the transmission into a different gear ratio can be generated in response to the generation by the signal processing means of the control unit of a signal having a characteristic which is a difference between the characteristics of signals from the one sensor. Furthermore, the second signal which denotes the intent to shift the transmission into a selected gear ratio can be generated in response to the generation, by the signal processing means of the control unit, of a signal which is a quotient of differences between the characteristics of a plurality of signals from the one sensor.
The signal generating means of the control unit can be designed to transmit to the adjusting means a second signal having a different threshold value for each of the plurality of gear ratios of the transmission in the power train.
Alternatively, the gear ratios of the transmission can be comprised of at least two groups, and the signal generating means of the control unit can be designed to transmit to the adjusting means a second signal having a different threshold value for each such group of gear ratios.
Still further, the signal generating means of the control unit can be designed to transmit to the adjusting means a second signal having a selected (given) threshold value for each of the plurality of gear ratios of the transmission.
If the power train is installed in a motor vehicle and the first signals include at least one signal denoting a threshold value, the processing means of the control unit can be designed to subject the at least one signal to at least one of a plurality of treatments including testing, evaluating, fixing and adapting as a function of at least one of: (a) time, (b) the condition of the motor vehicle (e.g., whether the engine of the vehicle is on or off), and (c) a least one specific event (e.g., a specific position of the throttle valve, the position of the gas pedal, etc.). The gear ratios of the transmission normally include a neutral gear and a plurality of additional gear ratios; the aforementioned treatment of the at least one signal can involve adapting the at least one signal during shifting of the transmission into the neutral gear or into one of the plurality of additional gear ratios. Alternatively, the at least one signal can be adapted while the transmission is already shifted into the neutral gear or into one of the additional gear ratios.
The power train can further comprise a prime mover (e.g., an internal combustion engine) having an idle condition and an operative condition, and the torque transmitting system in such power train can comprise an engageable and disengageable clutch. The second signals can denote an intent on the part of the operator of the motor vehicle to shift the transmission into a selected gear ratio, and the aforementioned treatment by the processing means of the control unit can include adapting the at least one signal to generate a second signal denoting the aforementioned intent while the clutch is disengaged and in response to the satisfaction or fulfillment of at least one of a plurality of prerequisites or specific events including (a) a relatively slow shifting of the transmission into a selected gear ratio, (b) a relatively rapid shifting of the transmission into a selected gear ratio, (c) shifting of the transmission into a selected gear ratio in the idle condition of the prime mover, (d) shifting of the transmission into a selected gear ratio in the operative condition of the prime mover, (e) shifting of the transmission out of a previously selected gear ratio, and (f) shifting of the transmission into a selected gear ratio irrespective of the condition of the prime mover.
If the power train is put to use in a motor vehicle and further includes a prime mover, and if the second signals are indicative of an intent on the part of the operator of the motor vehicle to shift the transmission into a selected gear ratio, the processing means of the control unit can include means for converting (a) the one signal, (b) the first signals, and/or (c) the treated signals into a second signal which causes the adjusting means to disengage, or to maintain in disengaged condition, a clutch (such as a friction clutch) of the torque transmitting system.
When the shifting of the transmission into a selected gear ratio is completed, the first signals can denote the position and/or the dynamics of the at least one external member.
If the power train forms part of a motor vehicle and the transmission further comprises means for holding at least one of the aforementioned plurality of components with a predetermined retaining force upon completion of the shifting of the transmission into a selected gear ratio, the at least one external member can be set up to complete or cover a movement from a first position to a second position in response to the application of a second force corresponding to the retaining force during shifting of the transmission into a first selected gear ratio, and such at least one external member is preferably movable to at least one third position. The first signals can be indicative of the position of the at least one external member, and the second signals can be indicative of an intent on the part of the operator of the motor vehicle to shift the transmission from the first selected gear ratio into a second selected gear ratio when the first signals indicate that the at least one external member has assumed one of the second and third positions.
Alternatively, the second signals can be indicative of an intent on the part of the operator of the motor vehicle to shift the transmission from the first selected gear ratio into a second selected gear ratio when the first signals indicate that the at least one external member has covered a distance at least matching the first distance.
If the transmission further comprises means for engaging at least one of the plurality of components (e.g., the at least one external member) with a predetermined retaining force upon completion of shifting of the transmission into a selected gear ratio, and if the second signals serve to indicate an intent on the part of the operator of the motor vehicle to shift the transmission from one selected gear ratio into another selected gear ratio, the at least one external member can be mounted for movement by the operator in response to the application of a second force which at least matches the retaining force. In such apparatus, the first signals can indicate the extent of movement of the at least one external member in response to the application of the second force. The processing means of the control unit in such apparatus is or can be designed to generate second signals denoting the intent on the part of the operator in response to the generation of a first signal denoting a predetermined extent of movement of the at least one external member.
Another feature of the invention resides in the provision of an apparatus for actuating an adjustable system for transmitting torque in a power train between a prime mover and a transmission of the type having a plurality of gear ratios and including a mobile external gear ratio selecting member, device or component, a mobile internal gear shifting device, member or component, and a connection between the external and internal devices. The apparatus comprises at least one first sensor having means for transmitting first signals denoting changes of the position of the external device, at least one second sensor having means for transmitting second signals denoting the position of the internal device, a control unit having means for processing the first and second signals and for generating third signals as a function of the first and second signals, and means for adjusting the torque transmitting system in response to the third signals. The torque transmitting system is or can be adjustable between an engaged condition and a disengaged condition, and it can comprise a clutch, e.g., a friction clutch. The external device can include a gear ratio selecting lever and at least one first element connected with the lever (such element can form part of the aforementioned connection), and the internal device can include a shaft and at least one second element connected with the shaft (again, such second element can form part of the connection).
A further feature of the invention resides in the provision of an apparatus for actuating an adjustable system which transmits variable torque in a power train between a prime mover and a transmission having a plurality of gear ratios and including an external device which is movable by an operator in dependency upon the magnitude of the torque being transmitted by the torque transmitting system to select the ratios of the transmission, an internal gear shifting device and a connection between the external and internal devices. The apparatus comprises at least one first sensor having means for transmitting first signals denoting changes of the position of the external device, at least one second sensor having means for transmitting second signals denoting the position of at least one of the external and internal devices, a control unit having means for evaluating the first and/or the second signals and for generating, as a function of the evaluated signals, third signals which indicate the intended movement of the external device by the operator, and means for adjusting the torque transmitting system in response to the third signals to permit or enable the torque transmitting system to transmit a torque which ensures that the operator can move the external device for the purpose of selecting a desired gear ratio. The torque transmitting system can include a clutch, e.g., a friction clutch. The external device can include a gear selecting lever, and the connection can include at least one element which is connected with the lever. The internal device can include a shaft, and the connection can further comprise at least one second element which is connected with the shaft.
An additional feature of the invention resides in the provision of an apparatus for actuating an engageable and disengageable system for transmitting variable torque in a power train between a prime mover and a transmission having a plurality of gear ratios and including an external device which is movable by an operator in dependency upon the magnitude of the torque being transmitted by the torque transmitting system to select the gear ratios of the transmission, a mobile internal gear shifting device, and a connection between the external and internal devices. The apparatus comprises at least one first sensor having means for transmitting first signals which indicate changes of the position of the external device, at least one second sensor having means for transmitting second signals which indicate the position of at least one of the external and internal devices, and a control unit having means for evaluating the first signals and/or the second signals and for generating, as a function of the evaluated signals, third signals which indicate the intended movement of the external device by the operator in response to the satisfaction or fulfillment of at least one of a plurality of conditions or prerequisites including (a) detection of movement of the external device through a predetermined distance to a threshold of an extent of movement which is necessary to change the ratio of the transmission, (b) detection of movement of the external device to or beyond a predetermined position, (c) detection of a difference between the characteristics of the first and second signals exceeding a predetermined threshold value, and (d) detection that a quotient of the differences between the characteristics of the first and second signals reaches, exceeds or is below a predetermined threshold value. Such apparatus further comprises means (such as a linkage, a fluid-operated unit or an electric motor) for disengaging the torque transmitting system in response to the third signals. The torque transmitting system can include a clutch, e.g., a friction clutch. The external device can include a gear ratio selecting or gear shift lever, and the connecting means can include at least one first element (e.g., a link) which is connected with the lever; the internal device can include a shaft and the connection can further include at least one second element which is connected with the shaft.
Still another feature of the invention resides in the provision of an apparatus for actuating an adjustable system for transmitting variable torque in a power train between a prime mover (such as a combustion engine) and a transmission of the type having a plurality of gear ratios and including an external device which is movable to select the gear ratios of the transmission, a mobile internal gear shifting device, and a connection between the external and internal devices. The apparatus comprises at least one sensor having means for transmitting first signals which are indicative of changes of the position of the external device, and a control unit having means for evaluating the first signals and for generating, as a function of the evaluated signals, second signals which indicate the intended movement of the external device by an operator of the external device in response to detection of a movement of the external device through a predetermined distance beyond thresholds of predetermined adapted extents of movement of the external device.
An additional feature of the invention resides in a combination of sensors which can be embodied in an apparatus for actuating an adjustable system for transmitting torque in a power train encompassing a prime mover and a transmission having a plurality of gear ratios and including a mobile external gear ratio selecting device and at least one first element connected with such external device, a mobile internal gear shifting device, and at least one second element connected with the internal device. At least one of the first and second elements is movable between a plurality of positions, and the transmission further includes a connection provided between the external and internal devices and including resilient means between the at least one first element and the at least one second element. The novel combination comprises at least one first sensor (e.g., a potentiometer or a Hall generator) having means for transmitting first signals denoting the position of the movable element, and at least one second sensor including means for transmitting signals denoting the positions of the at least one first element and/or the at least one second element. The external device can comprise a gear selector lever which is connected with the at least one first element.
A further feature of the invention resides in the provision of an apparatus for actuating an engageable and disengageable system for transmitting torque in a power train including a transmission having a plurality of gear ratios and comprising a plurality of mobile components including at least one external gear ratio selecting member, at least one internal gear shifting member, a first element connected with the at least one external member and a second element connected with the at least one internal member. The apparatus comprises at least one first sensor having means for generating first signals which indicate the positions of at least one of the at least one external member and the first element, at least one second sensor having means for generating second signals indicating the positions of at least one of the at least one internal member and the second element, a central control unit having means for evaluating the first and second signals and for generating third signals, and means for disengaging the torque transmitting system in a planned manner in response to the generation of third signals. The evaluating means comprises means for adapting, at preselected intervals, those signals from at least one of the sensors which denote at least one of (a) a movement of at least one of the mobile components through a distance denoting a threshold of a movement which is required to shift the transmission into a selected gear ratio, (b) a movement of at least one of the mobile components to a position of rest when the shifting of the transmission into a selected gear ratio is completed, and (c) a movement which is necessary to shift the transmission from one gear ratio to another gear ratio. The evaluating means further comprises means for establishing one of (A) a difference between the first and second signals, and (B) a quotient of a difference between the characteristics of first signals at instants t1 and t2 and of a difference between the characteristics of the second signals at the instants t1 and t2. The third signals are generated when the adapted signals are indicative of one of (a) completion of the determination of the threshold of movement, (b) completion of the determination of movement to the position of rest, and (c) completion of determination of movement to shift the transmission from the one gear ratio to the other gear ratio. The torque transmitting system can include a clutch, such as a friction clutch.
An additional feature of the invention resides in the provision of a method of controlling or regulating the operation of an apparatus for adjusting an engageable and disengageable system serving to transmit torque in a power train wherein a transmission has a plurality of gear ratios and includes at least one mobile external gear ratio selecting member, at least one mobile internal gear shifting member, and a connection between the external and internal members, wherein first and second sensors are provided to respectively transmit first and second signals denoting variable parameters of the transmission, and wherein a control unit comprises means for receiving the first and second signals. The method comprises the steps of evaluating the first and second signals in the control unit, generating in the control unit third signals on the basis of the evaluated first and second signals, and disengaging the torque transmitting system by way of an adjusting device when the evaluation of the first and second signals results in the generation of a third signal denoting an intent to shift the transmission into a selected gear ratio.
The method can further comprise the step of connecting the control unit with at least one electronic circuit for a constituent of the power train, e.g., for a prime mover or the transmission, or for an antiblock system in a motor vehicle.
The signals from at least one of the sensors can indicate a threshold value of a position of the at least one external member at which the second signal is indicative of an intent on the part of an operator to shift the transmission into a selected gear ratio.
Alternatively, the signals from at least one of the sensors can indicate a threshold value of a distance which is covered by the at least one external member when the second signal denotes an intent on the part of an operator to shift the transmission into a selected gear ratio.
The evaluating step can include evaluating the first and second signals at intervals, establishing a first difference between the signals which are transmitted by one of the sensors at an instant t1 and an instant t2, establishing a second difference between the signals which are transmitted by the other of the sensors at the instants t1 and t2, dividing one of the differences by the other of the differences, and utilizing the thus obtained quotient to ascertain a threshold of a movement which is to be carried out by at least one of the external and internal members to shift the transmission into a selected gear ratio.
Alternatively, the evaluating step can include evaluating the first and second signals at intervals, establishing a first difference between the signals which are transmitted by one of the sensors at an instant t1 and an instant t2, establishing a second difference between the signals which are transmitted by the other of the sensors at the instants t1 and t2, dividing one of the differences by the other difference, and utilizing the thus obtained quotient to effect a movement of at least one of the external and internal members to a position in which such at least one member is held with a predetermined retaining force while the transmission dwells in a selected gear ratio.
The evaluating step can also include generating a quotient of differences between the intensities and/or other characteristics of signals which are transmitted by one of the sensors and signals transmitted by the other of the sensors. The quotient is indicative of a gradient gs of movement to be completed by at least one of the external and internal members to shift the transmission from a first gear ratio to a different second gear ratio, and the third signal is generated when a parameter of the gradient gs at least approximates a characteristic value.
For example, the gradient gs can be ascertained by the control unit by resorting to the equation
gs=|ss(i)xe2x88x92ss(ixe2x88x921)|/|sG(i)xe2x88x92sG(ixe2x88x921)|
wherein ss(i) denotes a signal from one sensor at an instant i, and sG(i) denotes a signal from the other sensor at the instant i.
The signal ss(i) can denote a variable parameter of the external member, and the signal sG(i) can denote a variable parameter of the internal member. The signals ss(i) and sG(i) can be obtained as a result of a transformation with f(xcex1,xcex2) to a common zero point position and identical amplitude in accordance with the following equation:
gs=xcex1[|ss(i)xe2x88x92ss(ixe2x88x921)|+xcex2]/|sG(i)xe2x88x92sG(ixe2x88x921)|.
Alternatively, the evaluating step can include generating a quotient of differences between signals which are transmitted by one of the sensors and signals which are transmitted by the other sensor. The quotient can be indicative of a gradient gs of movement to be completed by at least one of the external and internal members in order to shift the transmission from a first gear ratio to a different second gear ratio. The third signal is generated when the gradient gs satisfies the equation
gs=xcex11[|ss(i)xe2x88x92s(s(ixe2x88x921)|+xcex21]/xcex12[|sG(i)xe2x88x92sG(ixe2x88x921)|+xcex22]
wherein the summands xcex21,xcex22 and/or the factors xcex11,xcex12 are selected in such a way that gs assumes a fixed value when the at least one external member performs a movement in synchronism with a movement of the at least one internal member. The fixed value can equal one. Furthermore, such fixed value can be a constant value.
Moreover, the evaluating step can include generating a quotient of differences between signals which are transmitted by one of the sensors and signals which are transmitted by the other sensor. The quotient is indicative of a gradient gs of movement to be completed by at least one of the external and internal members to shift the transmission from a first gear ratio to a different second gear ratio. The gradient gs equals one when the at least one external member is moved in synchronism with the at least one internal member, gs is greater than one when the at least one external member is moved at a speed exceeding that of the at least one internal member, and gs is less than one when the at least one external member is moved at a speed below the speed of the at least one internal member.
Still further, the evaluating step can include generating a quotient of differences between signals which are transmitted by one of the sensors and signals which are transmitted by the other sensor. The quotient is indicative of a gradient gs of at least one of (a) a threshold of movement to be completed by at least one of the external and internal members in order to shift the transmission from a first gear ratio to a different second gear ratio, and (b) a movement of at least one of the external and internal members to a position in which the shifting of the transmission into a selected gear ratio is completed. The gradient gs is fixed or is adapted to a value corresponding to the transition from a value greater than one to a value less than one.
Moreover, the evaluating step can include an adaption of signals which denote one of (a) a threshold of movement of the at least one external member, and (b) a position of dwell of the at least one external member in a selected gear ratio of the transmission, and this independently for each of the gear ratios.
The evaluating step can also include identical adaption of signals denoting one of (a) a threshold of movements of the at least one external member, and (b) a position of dwell of the at least one external member in a selected gear ratio for each of the gear ratios.
Still further, the evaluating step can include an adaption of signals denoting one of (a) a threshold of movements of the at least one external member, and (b) a position of dwell of the at least one external member in a selected gear ratio of the transmission during at least one predetermined stage of operation of the transmission. The at least one stage can involve a shifting of the transmission from a neutral gear ratio into another gear ratio. Still further, the at least one stage can involve a shifting of the transmission into the neutral gear ratio from one of the other gear ratios (such as forward ratios one to five and a reverse gear ratio). Moreover, the at least one stage can involve shifting the transmission into the reverse gear ratio or into the first forward gear ratio. The at least one stage can also involve a starting of the apparatus or a starting of the engine in a motor vehicle which embodies the power train.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved actuating apparatus itself, however, both as to its construction and mode of utilizing the same, together with numerous additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments of the apparatus, and of certain presently preferred specific embodiments of the improved method, with reference to the accompanying drawings.